The use of woven and nonwoven fibrous sheets in bagging materials has been described in the literature. In general, the nonwoven materials have been used in combination with other sheet products to provide laminates with a desired set of properties. Attempts have been made to construct porous shipping bags entirely of nonwoven polypropylene fibrous sheets of low weight and low cost. However, the fuzzing resistance has been poor causing contamination of the bag contents and an unsightly appearance. In addition, bags of the nonwoven sheet frequently are weak and will burst on being dropped even from low levels.
The present invention provides a solution to such problems with a thermally bonded continuous nonwoven fibrous sheet of polypropylene filaments which can be used in making a shipping bag with high drop strength, high fuzz resistance, low porosity (low sifting) and low basis weight. The bag is useful for shipping materials such as dry foods (e.g., peanuts or soybeans) and granular industrial materials.